Timing device

ABSTRACT

A timing device has a timing cam driven by a miniature electric motor through a clutch. Fixed directly to the forward axial end face of an output gearwheel of the clutch is an indicating member about the axis of turning of which extends an at least partannular scale giving a visual indication of the progress of timing. A spring urges the clutch to engage but is prevented by a spring-loaded armature of a solenoid of a relay from producing such engagement. However, on energization of the solenoid, the armature moves to allow the spring to produce such engagement. The spring-loading of the armature is provided by leaf-spring contact members on which the armature acts mechanically by way of an electrically insulating bar.

United "States Patent Inventor Jerzy Kazimierz Cuchla Harlow, England Appl. No. 740,231 Filed June 26, 1968 Patented Jan. 26, 1971 Assignee Electrical Remote Control Company Limited Harlow, Essex, England a British Company Priority Dec. 13, 1967 Great Britain 56,734/67 TIMING DEVICE 12 Claims, 1 Drawing Fig.

US. Cl 200/38 Int. Cl H0lh 7/08 Field of Search 200/38,

38A, 38Al, 38B], 38B, 38C, 38Cl; 74/35, 3.52

Primary Examiner-H. 0. Jones Attorney-Waters, Roditi, Schwartz & Nissen ABSTRACT: A timing device has a timing cam driven by a miniature electric motor through a clutch. Fixed directly to the forward axial end face of an output gearwheel of the clutch is an indicating member about the axis of turning of which extends an at least part-annular scale giving a visual indication of the progress of timing. A spring urges the clutch to engage but is prevented by a spring-loaded armature of a solemid of a relay from producing such engagement. However, on energization of the solenoid, the armature moves to allow the spring to produce such engagement. The spring-loading of the armature is provided by leaf-spring contact members on which the armature acts mechanically by way of an electrically insulating bar.

PATENTEU JANZB IBYI TIMING DEVICE According to one aspect of thepresentinvention, there is provided a timing device, comprising driving .means, a turnable-timing cam for turning by said means, a clutch interposed between said driving means and said cam and having an input member and an output member engageable to connect said driving means to said cam, an indicating member fixed directly to said output member, and an at least part-annular scale extending about the axis of turning of said indicating member for giving a visual indication of the progress of timing.

According to another aspect of the present invention, there is provided a timing device, comprising driving means, a turnable-timing cam for turning by said means, a clutch interposed between said driving means and said cam and engageable to connect said driving means to said cam, biassing means arranged to produce engagement of said clutch, means preventing said biassing means from producing engagement of said clutch, a solenoid for controlling said clutch, and an armature which, on energization of said solenoid, is attracted towards said solenoid and renders said preventing means ineffective, thereby to enable said biassing means to produce engagement of said clutch.

According to a further aspect of the present invention, there is provided an electrical relay, comprising a solenoid, an armature which is attracted towards said solenoid on energization of said solenoid, and first and second electrical contact members including a'leaf-spring contact member which opposes movement of said armature towards said solenoid, said armature acting mechanically on said leaf-spring contact member by way of electrical insulating material and displacing said leaf-spring contact member relatively to the other of said contact members on energization of said solenoid.

BRIEF DESCRIPTION OF THE DRAWING In order that the invention may be clearly. understood and readily carried into effect, reference will now be made, by way of example, to the accompanying drawing, which shows an exploded front perspective view of an electromechanical timing device.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, the timing device includes a miniature electric motor 1 which, through a pair of gearwheels 2 and 3, rotates a shaft 3A. Fixed to the forward end of the shaft 3A is an input gearwheel 4 of a clutch 4, 5. The output gearwheel 5 of the clutch is mounted on a spindle 6 so as to be free to rotate relatively thereto. Fixed directly to the rearward axial end face of the gearwheel 5 is a timing cam 5A and fixed directly to the forward axial and face thereof is an indicating member 5C, the member 5C extending away from the spindle 6 in exactly the same direction as the cam 5A. Fixed to the forward end of the spindle 6 is an adjustment pointer 7 which is movable over an at least part-annular scale 23 extending about the axis of the spindle 6. Fixed to the rearward end zone of the spindle 6 is a radially projecting disc 68 having a boss. A torsion spring 58 is fixed at one end to the gearwheel S and at the other end to the boss of the disc 68, and biases the gearwheel S, and thus the cam 5A, into the starting position. A stop 6A fixed to and projecting forwardly from the disc 68 defines the starting position of the cam 5A by limiting the movement of the cam 5A under the action of the return spring 58. The rearward extremity of the spindle 6 extends through an upright wall of a U-shaped fixed yoke 9, and, at the rearward side of this wall, is provided with a head 6C, between which and the wall is arranged a bow spring 6D which urges the head 6C away from the wall, and thus presses the disc 68 into frictional engagement with the front face of the wall. Thus, the spindle 6 is caused to remain in any angular position into which it has been put by manual rotation of the pointer 7. Between the pointer 7 and the scale 23 is arranged a transparent bezel 8. It will be appreciated that, not only is the starting position of the timing cam 5A set and indicated by the pointer 7 with reference to the scale 23, but the progress of timing can be seen by viewing the indicating member 5C through the central aperture in the scale 23. Fixed to the base of the yoke 9 is a solenoid 10 which, on energization, attracts an armature 9A having fixed thereto a bar 13 of electrically insulating material. Respective opposite end zones of the bar 13 bear on the forward ends of electrical contact members 14 and 17 in the form of leaf-springs. Above and below the contact members 14 and 17 are other contact members 15, 16, 18 and 19 which cooperate therewith. The contact members 14 to 19 are mounted in, and project at both sides of, a fixed upright wall 22 of electrically insulating material. The armature 9A is pivoted to an upright wall of the yoke 9 to which the wall 22 is fixed. On the other upright wall of the yoke 9 is mounted a lever 11 which carries rotatably the shaft 3A and is urged downwardly by a tension spring 12. By way of a projecting arm 11A, the lever 11 presses downwardly on the bar 13, but, provided that the solenoid 10 is not energized, the upward action of the leaf-spring'contact members 14 and l7fon the bar 13 prevents the lever 11 from moving the bar 13 downwardly under the action of the spring 12. Provided below the yoke 9 are two microswitches 20 and 21, between which is mounted a leaf-spring 24 for operating the same. At the end of its timing travel, the timing cam 5A is arranged to displace the leaf-spring 24 to operate the microswitches 20 and 21.

In use of the timing device, the pointer 7 is set to the desired starting position for the cam 5A, the gearwheel 5 following, under the action of the spring 58, the movement of the stop 6A. On energization of the solenoid 10, the bar 13 presses downwardly the contact members 14 and 17, so breaking the contact pairs 14, 15 and l7, l8 and making the contact pairs 14,16 and 17, 19. As the bar 13 descends, the spring 12 pulls the lever 11 downwardly, and so lowers the gearwheel 4 into mesh with the gearwheel 5, whereupon the timing operation commences. When the cam 5A strikes the leat spring 24, one of the microswitches 20 and 21 can, if desired, break the circuit of the solenoid l0, whereupon the contact members 14 and 17 displace the bar 13 and the armature 9A upwardly and so disengage the gearwheel 4 from the gearwheel 5. On such disengagement, the spring 58 returns the gearwheel 5 to its starting position. As the contact members 14 and 17 move upwardly, the contact pairs l4, l6 and 17, 19 are broken and the contact pairs l4, l5 and 17, 18 are made. Alternatively to having one of the microswitches 20 and 21 arranged in the circuit of the solenoid 10 it could be arranged in the circuit of ,the motor 1, deenergization of the solenoid 10 being subsequently brought about by some other means. The other of the microswitches 20 and 21, and all of the contact pairs 14 to 19 can be used to control the timing of some process.

The timing device described has the following advantages. Firstly, having the gearwheel 5, the cam 5A and the member 5C as a single part simplifies and cheapens construction of the timing device. Secondly, once the contact members 14 to 19 are mounted in the wall 22, they are immediately ready for making external connections, particularly soldered connections. If the armature 9A were to be used instead of the spring 12 to urge the gearwheel 4 towards the gearwheel 5, considerable buzzing of the relay 9A, 10, l3--l9, would occur when the clutch teeth met end-to-end, but this is here avoided.

lclaim:

l. A timing device comprising driving means, a turnabletiming cam adapted for being turned by said driving means, a clutch interposed between said driving means and said cam and having an input member and an output member engageable to connect said driving means to said cam, an indicating member fixed directly to said output member, and at least part-annular scale extending about the axis of turning of said indicating member for giving a visual indication of said indicating member for giving a visual indication of the progress of timing, a spindle on which said output member is mounted so as to be free to rotate relative thereto, an adjuster connected to said spindle for adjusting the starting position of said cam, and adjustment pointer connected to said spindle and movable over said scale for indicating said starting position, and biasing means biasing said cam into said starting position.

2. A device according to claim 1, wherein said cam is fixed directly to said output member.

3. A device according to claim 2, wherein said output member comprises a wheel having said cam fixed directly to one axial end face thereof and said indicating member fixed directly to the other axial end face thereof.

4. A device according to claim 1, wherein said cam is fixed directly to said output member, and said adjuster comprises a stop fixed to said spindle and limiting return movement of said cam, and means maintaining said stop in its adjusted position.

5. A device according to claim 4, wherein said maintaining means comprises a radial projection fixed against axial movement on said spindle, and second biasing means urging said radial projection into frictional engagement with a fixed wall.

6. A device according to claim 1, comprising further biasing means effective to produce engagement of said clutch, means preventing said further biasing means from producing engagement of said clutch, a solenoid for controlling said clutch, and an armature which, on energization of said solenoid, is attracted towards said solenoid and renders said preventing means ineffective, thereby to enable said further biasing means to produce engagement of the clutch.

7. A device according to claim 6, wherein said input member and said output member comprise an input gearwheel, and an output gearwheel meshing with said input gearwheel.

8. A device according to claim 7, further comprising a driving shaft connected to, said driving means, said input gearwheel fixed to said driving shaft, and a lever carrying said shaft and urged to turn in one sense bysaid preventing means and in the opposite sense by said further biasing means.

9. A device according to claim 7, wherein said preventing means includes return spring means for said armature.

10. A device according to claim 9, wherein said return spring means comprises an electrical contact member in the form of a leaf-spring which opposes movement of said armature towards said solenoid, said armature acting mechanically on said contact member by way of electrically insulating material and displacing said contact member relatively to another contact member on energi zation of said solenoid.

11. A device according to claim 10, wherein said armature has fixed thereto a bar of electrically insulating material, respective opposite end zones of said bar bearing on the firstmentioned contact member and on a further electrical contact member in the form of a leaf-spring.

12. A device according to claim 10, comprising a fixed wall, said contact members being mounted in, and each projecting at both sides of, said fixed wall. 

1. A timing device comprising driving means, a turnable-timing cam adapted for being turned by said driving means, a clutch interposed between said driving means and said cam and having an input member and an output member engageable to connect said driving means to said cam, an indicating member fixed directly to said output member, and at least part-annular scale extending about the axis of turning of said indicating member for giving a visual indication of said indicating member for giving a visual indication of the progress of timing, a spindle on which said output member is mounted so as to be free to rotate relative thereto, an adjuster connected to said spindle for adjusting the starting position of said cam, and adjustment pointer connected to said spindle and movable over said scale for indicating said starting position, and biasing means biasing said cam into said starting position.
 2. A device according to claim 1, wherein said cam is fixed directly to said output member.
 3. A device according to claim 2, wherein said output member comprises a wheel having said cam fixed directly to one axial end face thereof and said indicating member fixed directly to the other axial end face thereof.
 4. A device according to claim 1, wherein said cam is fixed directly to said output member, and said adjuster comprises a stop fixed to said spindle and limiting return movement of said cam, and means maintaining said stop in its adjusted position.
 5. A device according to claim 4, wherein said maintaining means comprises a radial projection fixed against axial movement on said spindle, and second biasing means urging said radial projection into frictional engagement with a fixed wall.
 6. A device according to claim 1, comprising further biasing means effective to produce engagement of said clutch, means preventing said further biasing means from producing engagement of said clutch, a solenoid for controlling said clutch, and an armature which, on energization of said solenoid, is attracted towards said solenoid and renders said preventing means ineffective, thereby to enable said further biasing means to produce engagement of the clutch.
 7. A device according to claim 6, wherein said input member and said output member comprise an input gearwheel, and an output gearwheel meshing with said input gearwheel.
 8. A device according to claim 7, further comprising a driving shaft connected to, said driving means, said input gearwheel fixed to said driving shaft, and a lever carrying said shaft and urged to turn in one sense by said preventing means and in the opposite sense by said further biasing means.
 9. A device according to claim 7, wherein said preventing means includes return spring means for said armature.
 10. A device according to claim 9, wherein said return spring means comprises an electrical contact member in the form of a leaf-spring which opposes movement of said armature towards said solenoid, said armature acting mechanically on said contact member by way of electrically insUlating material and displacing said contact member relatively to another contact member on energization of said solenoid.
 11. A device according to claim 10, wherein said armature has fixed thereto a bar of electrically insulating material, respective opposite end zones of said bar bearing on the first-mentioned contact member and on a further electrical contact member in the form of a leaf-spring.
 12. A device according to claim 10, comprising a fixed wall, said contact members being mounted in, and each projecting at both sides of, said fixed wall. 